TY  - JOUR
DA  - 2000//
VL  - 77
SP  - 1182
EP  - 1184
AU  - Niquet, Yann-Michel
AU  - Allan, Guy
AU  - Delerue, Christophe
AU  - Lannoo, Michel
TI  - Quantum confinement in germanium nanocrystals
DO  - 10.1063/1.1289659
LA  - Anglais
SN  - 0003-6951
AB  - The electronic structure of Ge nanocrystals is studied using a sp3 tight binding description. Analytical laws for the confinement energies, valid over the whole range of sizes, are derived. We validate our results with ab initio calculations in the local density approximation for smaller clusters. Comparing to experimental data, we conclude that, similar to the case of silicon: (a) the blue-green photoluminescence (PL) of Ge nanocrystals comes from defects in the oxide and (b) the size dependent PL in the near infrared probably involves a deep trap in the gap of the nanocrystals. We predict that the radiative lifetimes remain long in spite of the small difference (0.14 eV) between direct and indirect gaps of bulk Ge.
PB  - American Institute of Physics
JO  - Applied Physics Letters
ER  - 
